ABSTRACT Originally awarded in 1976, this application requests a five-year renewal of the T32 Training Program in Immunology at the Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center (MSK). The objective of this Training Program is to provide junior postdoctoral fellows a solid foundation in the field of Immunology and to direct their interests towards important aspects of the immune system and its response to infectious agents, self antigens, and cancer. Three postdoctoral positions are requested for this competitive renewal. The duration of training for each trainee will be up to three years. The Training Program provides trainees with the intensive training, resources and experience necessary for them to develop successful careers in academia, government, and industry as independent researchers, mentors, and leaders. Areas of research training include tumor immunity and immune-oncology, bone marrow transplantation, lymphocyte and myeloid cell differentiation and biology, cell signaling, microbiota-host interactions, innate immunity, infectious immunity with a focus on cancer patients related infections. The objective of the Training Program is achieved by providing a structured environment with intensive involvement in immunology research, further strengthened by attendance at weekly seminars and research-in-progress meetings, monthly research colloquia and translational research seminars and an annual retreat. Trainees are also expected to participate in advanced courses covering contemporary topics of immunology and workshops on bioinformatics and grant writing skills. The major part of the training comes from the research experience under the tutelage of preceptors who are engaged in cutting-edge immunology research, with bearing on cancer and tumor immunity and related aspects of immune cell development and function at molecular, cellular and organismal levels. Trainees will be also taking advantage of the extensive interdisciplinary collaborations between members of the Immunology Training Program and respected outside scientists, both locally and nationally.